Causes

In many cases the causative factor is unknown and it is known as primary or essential hypertension.
When the cause of hypertension is established it is known as secondary hypertension.

Hypertension is caused due to various multiple risk factors like

• Family history of the disease.
• Obesity.
• Stress.
• Smoking tobacco.
• High fat and high sodium diet.
• Extremely nervous and highly emotional people.
• Kidney failure is the cause as well as the effect of hypertension.
• Diseases like renal artery failure, metabolic disorders, central nervous system disorders, endocrine disorders.
• Oral contraceptive pills.
• Steroids.
• Toxemia of pregnancy.

Clinical Features

A wide range of signs and symptoms are observed in various cases

• Severe headache usually in the morning.
• Nausea and vomiting.
• Dizziness and fainting attack.
• Bleeding from the nose.
• Easy fatigability.
• Palpitations (awareness of the heart beat).

Complications

Arteriosclerosis: High blood pressure harms the arteries by making them thick and stiff. This speeds the build–up of cholesterol and fats in the blood vessels the way rust and dirt collect in a pipe. This prevents blood from flowing through the body, and in time can lead to a heart attack or stroke.
Heart attack: Blood carries oxygen to the body. When the arteries that bring blood to the heart muscle become blocked, the heart cannot get enough oxygen. Reduced blood flow can cause chest pain (angina). Eventually, the flow may be stopped completely, causing a heart attack.
Heart failure: High blood pressure causes the heart to work harder. Over time, this causes the heart to thicken and stretch. Eventually, the heart fails to function normally, causing fluids to back up into the lungs. Controlling high blood pressure can prevent this from happening.
Kidney damage: The kidneys act as filters to rid the body of wastes. Over a number of years, high blood pressure can narrow and thicken the blood vessels of the kidneys. The kidney filters less fluid, and waste builds up in the blood. They may fail altogether. When this happens, medical treatment (dialysis) or a kidney transplant may be needed.
Stroke: High blood pressure can harm the arteries, causing them to narrow down faster. So, less blood can get to the brain. If a blood clot blocks one of the narrowed arteries, a stroke (thrombotic stroke) may occur. A stroke can also occur when very high pressure causes a break in a weakened blood vessel in the brain (hemorrhagic stroke).
Other complications include a confused state of mind, retinal hemorrhage and can even cause paralysis.